Gas Gauge Calibration
 

Today I found out my gauge was not really reading what I thought I had in the tank. A little under a 1/4 on the gauge and the tank was really the bottom of the tank and the dregs of many years of fill ups. So cleaned things up and now I set the plastic float the vendors sell that the new gas doesn't attack on the bottom of the tank so it reads zero with out fuel. I now should have some reserve I believe when it reads zero as the fuel would need to cover I think at least half of the float to get it to move. Anyone agree with that?. And what do most of you read on your gauge when the fuel level is filling half of the round window?. What reading do you think was there when the A's were new?. I have a 31 with the indented firewall which I was told holds 1 more gallon than the earlier tanks?.

Re: Gas Gauge Calibration
 

I believe the 30-31 tanks hold 1 gallon more than the 28-29.

Re: Gas Gauge Calibration
 

Out of curiosity, as I have not filled my 30a tank, should it hold, and how far should it take me?

Re: Gas Gauge Calibration
 

When the gas is sitting in the middle of the glass my gauge reads full, and that’s where I usually fill to. Not sure if that’s right or not.

Re: Gas Gauge Calibration
 

A 31 holds 11 gallons.

Maybe someone has the specs on the gas tank stick. I made one up and it is very accurate, but per usual I can not find my file.

You will be able to bend the float wire to measure up with the tank stick.

I hope that someone can find the measurements for the stick for you.

Re: Gas Gauge Calibration
 

I copied this some time ago.
Back on to the calibrated gas gauge “stick”; it is made from a ¼” dowel rod and measures 11-5/8” from the tip to the end of the inexpensive-wood-drawer-knob. The measurements – if you are inclined to make one for your self – are 1 gal = 1-11/16”; 2 gal = 2-5/8”; 3 gal = 3-7/16”; 4 gal = 4-1/16”; 5 gal = 4-11/16”; 6 gal = 5-1/4”; 7 gal = 5-7/8”; 8 gal = 6-1/2”; 9 gal = 7-1/16”; 10 gal = 7-3/4”; and 11 gal = 8-5/8.” After filing a shallow grove at these levels and labeling every other grove using a wood burner, I shellacked the stick. It’s served as a backup for 34 years (yes, I do have an operable gas gauge) and I just toss it on the package tray behind the seat when not in use. Not exactly high-tech but then…

Re: Gas Gauge Calibration
 

Good idea for the stick. Would the measurements from the bottom be the same for a 1929 10 gallon tank?

Re: Gas Gauge Calibration
 

Unlike a Model T, wouldn't one be required to remove the factory supplied screen/spark arrestor to "dip stick" the tank ? I believe I'd rather calibrate my stock gauge.

Re: Gas Gauge Calibration
 

Good point. I don't have a cork float that might "gas-log" over time and sink to give a false reading. The brass float should be fine, once I adjust it.

Re: Gas Gauge Calibration
 

To answer the second part of #3, most model A's get something like 18-20 miles per gallon. A little less if only in-town stop and go driving.

Re: Gas Gauge Calibration
 

I just replaced a brass float that sank to the bottom after several years of floating. They sometimes develop pin holes.


TerryO

Re: Gas Gauge Calibration
 

Here is a Video on adjusting the gauge...Worked for me... Chap


https://www.youtube.com/watch?v=ucSV66JVyDc

Re: Gas Gauge Calibration
 

My 1929 Tudor read ~ 1/2 when gas level covers half of the glass. I still have the original glass with a magnifier in the center. .

When I fill the tank to the top. I can read the F and the gas level line is filling almost all the glass.

Car was restored by someone else and that person did the calibration. I only replaced the gaskets and that's why I know about the glass.

Re: Gas Gauge Calibration
 

I figure that the gauge is most needed when the fuel is low so I set mine to read empty when the float is on the bottom of the tank. When that happens, I know I am low on juice and I'd better do something about it. If I push my luck, I can still get an idea of what's happening in there by swerving the car and watching to see if the guage moves. Any splash of fuel in there will cause it to move slightly. If I get no movement, I get ready for a walk!
When the tank is full, I can see the fuel in the glass so the guage is redundant. In my earlier cars (smaller tank) I allow 200 miles per fill with some in reserve. When we are outback and towing the camper (which weighs about the same as the car - about a tonne), I allow 200 km. ANY mechanical fuel guage is only an indication of how much fuel you have. After that, it's about knowing your car, IMO.

Re: Gas Gauge Calibration
 

Put in a gallon, bend rod so it shows zero. (so you have a little reserve)

Re: Gas Gauge Calibration
 

30 and 31 gas tanks hold 11 gallons. I adjusted the float so that at empty I have approx. 1 1/2 gallons remaining. I also went to a specialty auto paint store and told the tech that I wanted to paint a 1/4" red stripe at the "empty" line on the floating gauge so that I could easily read empty while driving (I'm 75 years old) and know that I have a reserve. He mixed up a 1 oz. vial ($10) of gas resistant paint and said that after painting let it sit at room temperature and cure for 30 days before installing in the gas tank; I followed his advise. After 2 plus years the line is as clear as day. Although this will deduct points in a judging it gives me piece of mind while driving (I'm not into judging). A footnote: a Model A friend of mine borrowed my paint and painted his gauge but reinstalled it a few days later; the paint quickly dissolved.

Re: Gas Gauge Calibration
 

If you were to have it judged, just have enough fuel in it so the empty mark is hidden!!

Re: Gas Gauge Calibration
 

Replaced my gas gauge today. Likely could have reused the original with some good cleanup, but I had the new one, so installed it. Interesting the difference in the arms.
I had an empty tank , so zeroed it at E. I need to know the real empty.
Noted the old unit looked like it had a old cork style gasket. New one is rubber.